The present invention relates generally to disc type refiners, particularly pressurized disc type refiners having a rotating disc with refiner surfaces on both sides thereof juxtaposed between a pair of non rotating refiner plates.
Twin disc type refiners are well known, particularly in the paper making field and essentially comprise juxtaposed annular refining surfaces which are arranged for relative rotation so that material to be refined is introduced at the inner edge of the surfaces and is transported between the surfaces and peripherally discharged in a refined condition. The twin refiners typically include a central rotating disc having attrition plates on each side thereof cooperating with oppositely disposed rotationally fixed attrition plates. One or both of the non rotating plates are supported on heads that are axially adjustable to vary the plate spacing and the shaft carrying the rotating head may be either axially adjustable or free floating.
Many commercial units are based on the above general operation. For example, commercial twin refiners are manufactured by the following companies: Beliot Jones; Black Clawson; Balton Emerson; Morden; and Koppers-Sprout Waldron (assignee of the subject application). All of the units heretofore manufactured by the above companies have found acceptance in the industry but still have one or more drawbacks. For example, during the normal operation of the refiner the attrition plates wear out and must be periodically replaced. The periodic replacement of refiner plates usually takes about 5 to 6 hours because of the difficulty in getting access to all the refiner plates. In all of the prior art twin refiner units, it is necessary to move the rotating center disc or to actually remove the rotating center disc to gain access to all the refiner plates. It is also necessary in some of the prior art refiners to disrupt the normal shaft sealing surfaces from each other during the plate changing operation. Also, all of the prior units have inlets at or near the top of the unit which enter the unit at a vertical angle. This location of the inlet or inlets almost requires the use of overhead piping.
According to the present invention, an improved twin refiner is provided for overcoming the foregoing described drawbacks of the prior art refiners. The twin refiner of the present invention provides for the independent axial movement of both of the non rotating refiner plates away from the rotating refiner plates for easy access to all of the refiner plates. The improved refiner allows access to all of the refiner plates at the same time and without any necessity of moving the rotating center disc and without the necessity of disrupting the normal shaft sealing surfaces.
The improved disc type refiner of the present invention includes a base with an integral housing supported by the base, a drive shaft extending through the housing, means on the housing for rotatably supporting the drive shaft, a pair of non rotating plate holders mounted within the housing in spaced opposed relation, a rotating disc mounted on the drive shaft between the non rotating plate holders, refiner plates disposed on each side of the rotating disc in parallel juxtaposed relation to refiner plates disposed on the adjacent non rotating plate holders, means connecting the drive shaft and rotating disc to provide rotation of the disc with the shaft, means for permitting axial movement of the shaft and rotating disc, means for permitting axial adjustment of one of the non-rotating plate holder, inlet means for conveying material to be refined into the housing between the juxtaposed refining plates, means for removing the refined material from the housing, means for adjusting the axial position of at least one of the non rotating plate holders, and means for moving both non rotating plate holders with plates axially away from the rotating disc for easy access to all the refiner plates.
The rotating disc refiner of the present invention also provides for one or two horizontal inlets on the side along the center line of the refiner. In this position the inlets give the refiner user the flexibility of running the piping either overhead or under the floor.
The improved refiner of the present invention also has a mechanical stop means for limiting the axially adjustable non rotating refiner plates from disengaging the peripheral seal between the plate holder and refining cavity during operation. The volume of material passing through the refiner may have a flow rate of from 200 gal/min to over 7,000 gal/min and any disengagement of the peripheral seal would have serious adverse effects.
Many patents have issued on twin refiners. For example, see Fisher, U.S. Pat. No. 3,276,701; Fisher, et al., U.S. Pat. No. 3,893,631; Fisher, U.S. Pat. No. 3,701,488 and Jones et al., U.S. Pat. Nos. 2,690,098 and 2,727,440. All of the above patents have been considered but do not show the improved aspects of the present invention. The present invention is particularly concerned with an improvement of the type of twin refiner disclosed in Fisher, U.S. Pat. No. 3,276,701 and the disclosure in that patent is hereby incorporated by reference.
Other objects and advantages of this invention will become more apparent from the following description, the accompanying drawings and the appended claims.